1. Field of the Invention
The present invention relates to a CAD system, in particular a pattern design editor for enabling interactive pattern design on a display from a workstation, and to an editing method of the same.
As an example of the work involved in pattern design, mention may be made of the disposition of a large number of electronic devices on a printed circuit board, the interconnection of these by conductors, and the formation of a graphic comprised of the conductors on the printed circuit board.
The functions of automatic configuration and automatic interconnection for designing patterns on a printed circuit board have been greatly automated and improved by the development of CAD systems. No matter how highly automated, however, complete automation of automatic configuration and automatic interconnection is difficult. Therefore, there are many areas in which human intervention for editing through an editor is necessary in a CAD system.
Accordingly, there has been a strong demand for increasing the efficiency of the manually performed editing work. The present invention relates to a CAD system answering this demand.
2. Description of the Related Art
In a general CAD system, there is a broad range of manually performed editing work in which greater efficiency is desired. The present invention takes note of the three types of work which form the basics of pattern design and which are closely related with each other.
The first is the work for designating the type of the editing processing, for example, "movement", "deletion", "copying", etc. of an element to be processed (a component, interconnection, land, etc.) and the work for designating the element to be processed.
The second is the work for editing the above element, in particular, an element having a complicated shape. For example, in pattern design on a printed circuit board, reduction of noise requires the formation of earth conductors of as large an area as possible while avoiding short circuits with other elements (lands, interconnections, pins, vias, etc.)
The third is the work for changing a once input parameter (data specifically defining element) due to some reason or another in the middle of the first or second type of work and the work for initializing and canceling information previously input due to some reason or another in the middle of the work.
The above first to third types of work had been performed as follows in the prior art.
First, the work for designating the type of the editing processing had been performed as follows in the related art. When the editing processing (for example, movement, deletion, copying, etc.) was to be performed on the display of the CAD system, the designer first called up on the display a menu showing the different types of editing processing, then operated a button of a pointing device, for example, a mouse, to instruct the type of editing processing desired.
After instructing the type of the editing processing (for example, movement), the designer used the mouse to move the cursor and select the element (for example, electronic device) on the display to be moved.
After this, the designer used the cursor to specify the position to be moved to.
Next, the work for editing an element having a complicated shape had been performed as follows in the related art.
Taking as an example the above earth conductor, a conductor is a N-gonal (N being an integer of 3 or more) broad area conductor. The designer used a pointing device, for example, a mouse, to select the N number of salient points of the N-gon on the display of the CAD system so as to input the coordinates of the salient points. Next, the designer edited the broad area N-gonal conductor pattern having the input coordinates as its salient points.
Next, the work for changing a once input parameter in the middle of the pattern design and the work for canceling (initializing) the already input information in the middle of a design had been performed as follows in the related art.
For example, assume that during execution of a command for input of a certain element, the parameters of that element are designated once by the editor. Alternatively, assume that the coordinate data and other information have already been input in the editor.
Assume further that for some reason or another, there is a request for changing a parameter or a request for initializing (canceling) the input information.
In such a case, since the parameter or the information were input during a certain command, when the designer wanted to change the parameter or initialize the input information in the middle of the design, he had to first end the execution of the command or else was not able to change the parameter or initialize the input information.
There were, however, the following problems in the related art.
When performing the above editing processing (for example, movement, copying, etc.), the designer had to always execute two operations, that is, selection of the type of editing processing from the menu and selection of the element to be subjected to the editing processing on the display. These two operations had to be performed very frequently. Therefore, the work involved in this editing became greater and the efficiency of pattern design became poorer.
Further, the "N" in the broad area N-gonal conductor generally may be as large as several thousands. Erroneous input was easy and correction of erroneous inputs was difficult. For these reasons, the efficiency of pattern design was further reduced.
Sometimes a function of inputting in the form of rectangles is provided as a method of instruction, but when switching from the usual input by salient points to input by rectangles, it is necessary to end the execution of the editing command once, so there is still the problem of reduction of the efficiency of pattern design.
Further, when instructing by input of rectangles, there is the disadvantage that it is not possible to instruct by input of a rectangle having a side in a direction intersecting the horizontal and vertical directions, that is, an inclined side.
When changing a parameter or initializing input information, further, it was necessary to end the execution of the command by which the parameter or input information had been input, so the designer had to perform further operations and again the efficiency of the pattern design was reduced.